Mr Vance challenged the fact-check to criticise the temporary protected status programme that the Haitians in question had used, leading Mr Walz to interject with a defence of the policy. Both men’s microphones were swiftly muted.

Ahead of the debate, CBS said its moderators would urge the candidates to fact-check each other, but said the network’s hosts could also choose to clarify a point if they decided it was left unclear.

The hot topic - immigration

Immigration dominated the debate, with Mr Vance accusing Ms Harris of abdicating her responsibilities and claiming he had been to the border more than the sitting vice president.

The Ohio senator went on to promote Trump’s hardline approach of mass deportations and building a border wall as he claimed between 20 and 25million people had entered the country illegally.

Some independent analysis suggests the figure is closer to half that.

Polls show that a majority of Americans rank immigration and border security as top priorities in the White House race and many support more restrictive policies.

Mr Vance went on to link the border crisis to America’s opioid epidemic.

He invoked his own mother’s years-long battle with opioids as he suggested “people who are struggling with addiction” could be “deprived of their second chance because Kamala Harris is letting fentanyl into our communities at record level”.

Vance puts his family front and centre

It was a tactic Trump’s running mate returned to throughout the 90-minute debate in questions spanning everything from the raging conflict in the Middle East to domestic manufacturing.

Tuesday night’s debate, likely to be the final one of the 2024 campaign, was also an opportunity for the two men who could be the country’s next vice president to introduce themselves to voters.

Mr Vance cast himself as a family man, repeatedly invoking his children and describing his humble origins in a former steeltown in Ohio.

He talked repeatedly about his mother, his wife Usha (pictured below) and their three children.

The 40-year-old appeared assured and confident as he parried questions on his past criticisms of Trump, 78, whom he once reportedly called “America’s Hitler”, simply saying he had been “wrong” about his new boss.

Mr Walz focused repeatedly on Mr Vance’s past comments, seeking to sow division between the Republican ticket and perhaps rile Trump, watching at home, into an angry response.

The 60-year-old is a relative newcomer to the national political stage despite serving six terms in the US congress and in his second term as Minnesota’s governor.

Aide described him as “nervous” ahead of the live televised showdown, on display on Tuesday night as he stumbled over his words at times, mixing up Iran and Israel in his opening answer.

The subject most fraught with political jeopardy

Mr Vance, a hardliner on abortion rights, sought to portray himself as a compassionate conservative, citing his friendships with people who disagreed with him on the issue and conceding many voters in his home state had rejected his stance.

The subject is fraught with political jeopardy for Trump and Vance, with their core base supporting a more restrictive approach to abortion access than the majority of the country.

Mr Vance attempted to strike a balance, positioning his stance as a desire to make it “easier” for women to have children by making fertility treatment and the cost of raising children more “affordable” while conceding Republicans had to do better at “earning Americans’ trust back” on the issue.

Mr Vance also said he opposed a national abortion ban and denied ever supporting one.

However in 2022 while running for the Senate in Ohio, Mr Vance said he “would like abortion to be illegal nationally”.

Trump deflected the question of a national abortion ban during his own debate.

Mr Walz said he agreed with many of Mr Vance’s comments. “His running mate though, does not, and that’s the problem,” he added, as he attempted to widen the wedge between Mr Vance and Trump on the issue.

The Democratic candidate was pictured (below) after the debate a pizzeria with his wife Gwen.

Both dodge questions on Middle East

The debate’s opening question focused on the ongoing conflict in the Middle East.

Moderators asked both candidates if they would support a pre-emptive strike by America’s ally Israel on Iran to disrupt the development of the Islamic republic’s nuclear programme.

Neither answered the question directly, with Mr Walz immediately pivoting to Trump’s foreign policy record, linking the current crisis to the ex-president’s withdrawal from the 2015 nuclear deal with Iran.

“Iran is closer to a nuclear weapon because of Donald Trump’s fickle leadership,” he said.

It comes as the war in the Middle East escalated hugely in the last 48 hours, including Iran launching more than 100 missiles at Israel.

Mr Vance hit back by pointing out the current crisis had only begun under the Biden-Harris administration.

He said: “Who has been the vice president for the last three and a half years? The answer is your running mate, not mine.”

“As much as Governor Walz just accused Donald Trump of being an agent of chaos,” he said, it was the Republican former president who had established “effective deterrence.”

Climate change

As the debate turned to the current storm ravaging parts of the US and environmental policy, Mr Walz said Democrats were focused on creating green jobs while Trump had labelled climate change “a hoax”.

The Democrat said Trump had even joked rising sea levels would lead to “more beachfront property”.

It’s the economy, stupid

Mr Walz deftly pivoted from climate change policy to make the case for boosting America’s energy production and attacking Trump’s aggressive protectionist trade policies.

“Donald Trump was the guy who created the largest trade deficit in American history with China,” he said, while workers’ right to “collectively bargain” was undercut.

Mr Walz also accused Trump of granting tax breaks “to the wealthiest” and claiming the Republican ex-president “hasn’t paid any federal tax in the last 15 years”.

Vance accuses Harris of Covid censorship

Mr Vance downplayed Trump’s refusal to concede the 2020 election and his role in the Jan 6, 2021 Capitol riot during which his supporters delayed the certification of Joe Biden’s victory.

Mr Walz said his Republican counterpart Mr Vance was helping to deny “the first time in American history that a president or anyone tried to overturn a fair election and the peaceful transfer of power”.

Mr Walz challenged Mr Vance to declare his running mate had lost the 2020 race.

“I’m focused on the future,” Mr Vance said, a response which Mr Walz branded a “damning non-answer”.

Trump has also refused to unconditionally accept the outcome of the 2024 race.

Mr Vance countered that the real threat to democracy was censorship of political opponents, which he claimed Ms Harris was engaged in “on an industrial scale”.

“She did it during Covid. She’s done it on a number of other issues. That is a much bigger threat to democracy than what Donald Trump said when he said protesters should peacefully protest on January 6th,” Mr Vance said.